Abstract: The invention relates to a process for recovery of rubber-modified vinyl(co)polymer from a polycarbonate resin or an optionally shredded molded part made thereof and the use of the recovered rubber-modified vinyl(co)polymer for the production of molded parts as well as blend partner in polycarbonate blends. Further optional aspects are the recovery of aromatic and/or aliphatic diol and the use of this diol for the production of polycarbonates.

Abstract: A multi-stage process for continuous production of a polysiloxane-polycarbonate block copolymer by polycondensation is disclosed where in a first stage an oligocarbonate and a hydroxyaryl-terminated polysiloxane are provided and in a second stage at least one special condensation reactor is used. A certain amount of a particular co-catalyst is added and this co-catalyst is added upstream of the first special condensation reactor. The polysiloxane-polycarbonate block copolymer produced by the process according to the invention has a high proportion of small polysiloxane domains and features good mechanical properties, in particular tough fracture behaviour in the notched impact test according to ISO 7391/ISO 180A, good processability, for example in injection moulding or in extrusion, and good flowability.

Abstract: A continuous process for producing a polysiloxane-polycarbonate block copolymer by polycondensation, comprising use of at least one thin-film evaporator, where this at least one thin-film evaporator includes at the circumference at least two wiper blade elements which rotate in the at least one thin-film evaporator. An oligocarbonate is reacted with a hydroxyaryl-terminated polysiloxane to afford a polysiloxane-polycarbonate block copolymer. In the reaction of the oligocarbonate with the hydroxyaryl-terminated polysiloxane using at least one thin-film evaporator, certain process parameters are observed. The polysiloxane-polycarbonate block copolymer produced has a small volume fraction of large polysiloxane domains at simultaneously narrow size distribution of the polysiloxane domains and exhibits good mechanical properties, in particular tough fracture behaviour, good processability, and good flowability.

Abstract: The present inventions relates to the preparation of 3,3,5-trimethylcyclohexylidene bisphenol. Especially, the present invention relates to the preparation of 3,3,5-trimethylcyclohexylidene bisphenol from 3,3,5-trimethylcyclohexanone and phenol in the presence of a gaseous acidic catalyst. The preparation comprises a first drying step and a second drying step wherein in the second drying step the temperature is increased in comparison to first drying step or in the second drying step the pressure is lowered in comparison to first drying step, or in second drying step both the temperature is increased and the pressure is lowered in comparison to the first drying step (d1).

Abstract: The present inventions relates to the preparation of 3,3,5-trimethylcyclohexylidene bisphenol. Especially, the present invention relates to the preparation of 3,3,5-trimethylcyclohexylidene bisphenol from 3,3,5-trimethylcyclohexanone and phenol in the presence of a gaseous acidic catalyst. The preparation comprises a first drying step and a second drying step wherein in the second drying step the temperature is increased in comparison to first drying step or in the second drying step the pressure is lowered in comparison to first drying step, or in second drying step both the temperature is increased and the pressure is lowered in comparison to the first drying step (d1).

Abstract: The present invention relates to the preparation of 3,3,5-trimethylcyclohexylidene bisphenol (BP-TMC). Especially, the present invention relates to the preparation of 3,3,5-trimethylcyclohexylidene bisphenol (BP-TMC) from 3,3,5-trimethylcyclohexanone (TMC-one) and phenol in the presence of a gaseous acidic catalyst. The preparation is preferably conducted continuously. It is an object of the present invention to prevent that solids, especially crystallized BP-TMC, more especially crystallized BP-TMC-phenol-adduct, block the outlet of the dosing valve for the gaseous acidic acid when the gaseous acidic acid is dosed into the reaction mixture comprising TMC-one and phenol in a reaction vessel.

Abstract: The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Abstract: The invention concerns a method for producing diaryl carbonates from monophenols and phosgene or chloroformic acid aryl esters in the presence of at least one optionally substituted pyridine or the hydrochloride salt thereof as catalyst, and the recovery and reinjection thereof back into the method. The method is carried out at least partially in a liquid phase without the use of an additional solvent, the catalyst being separated by means of distillation and recovered.

Abstract: The invention concerns a method for producing diaryl carbonates from monophenols and phosgene or chloroformic acid aryl esters in the presence of an optionally substituted pyridine or the hydrochloride salt thereof as catalyst, and the recovery and reinjection thereof back into the method. The method is carried out at least partially in a liquid phase without the use of an additional solvent, the catalyst being separated by means of crystallization and recovered.

Abstract: The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Abstract: The invention relates to polycarbonates with extremely low residual levels of volatile constituents and thermal degradation products, and also improved optical properties, especially Yellowness Index (YI) and good thermal stability, from solvent-containing polymer melts. The invention further relates to an apparatus and a process for preparing these polycarbonates with the aid of a devolatilizing extruder with at least three devolatilizing zones, and zones for introducing entraining agent into dispersion are present upstream of at least three devolatilizing zones.

Abstract: The invention relates to an efficient continuous method for producing polycarbonates according to the phase interface method.

Abstract: The present application relates to a method for the continuous production of diaryl carbonate from phosgene and of at least one monohydroxy compound (monophenol) in the presence of catalysts, and to the use thereof for the production of polycarbonates.

Abstract: The invention concerns a method for producing diaryl carbonates from monophenols and phosgene or chloroformic acid aryl esters in the presence of an optionally substituted pyridine or the hydrochloride salt thereof as catalyst, and the recovery and reinjection thereof back into the method. The method is carried out at least partially in a liquid phase without the use of an additional solvent, the catalyst being separated by means of crystallization and recovered.

Abstract: The invention concerns a method for producing diaryl carbonates from monophenols and phosgene or chloroformic acid aryl esters in the presence of at least one optionally substituted pyridine or the hydrochloride salt thereof as catalyst, and the recovery and reinjection thereof back into the method. The method is carried out at least partially in a liquid phase without the use of an additional solvent, the catalyst being separated by means of distillation and recovered.

Abstract: The present invention relates to a continuous process for producing lower dialkyl carbonates as a main product and alkylene glycol as a by-product by transesterification of a cyclic alkylene carbonate (e.g. ethylene or propylene carbonate) with lower alkyl alcohols in the presence of a catalyst and also the necessary purification of the dialkyl carbonate in a subsequent process step. For optimization of the economic efficiency and energy efficiency of the process, additional devices are used for intermediate heating of the internal liquid streams within the apparatus.

Abstract: The invention provides a process for preparing diaryl carbonates from dialkyl carbonates and aromatic hydroxyl compounds using at least two reaction columns, a process section for recovering the dialkyl carbonate used in the reaction and for removing the alcohol of reaction, one or more process steps for removing the by-products obtained in the process which have a boiling point between that of the dialkyl carbonate and that of the alkyl aryl carbonate formed during the preparation of the diaryl carbonate, and a process step for further purification of the diaryl carbonate obtained from the reaction columns.

Abstract: A process for preparing diaryl carbonate and utilizing at least part of the process wastewater by increasing the concentration of the wastewater phases containing sodium chloride for the electrolysis by means of osmotic membrane distillation with simultaneous dilution of the sodium hydroxide solution obtained from the electrolysis for the diaryl carbonate production process (diphenyl carbonate process) is described.

Abstract: The present invention relates to a continuous process for preparing lower dialkyl carbonates as main product and alkylene glycol as by-product by transesterification of a cyclic alkylene carbonate (e.g. ethylene carbonate or propylene carbonate) with lower alkyl alcohols in the presence of a catalyst and also the required purification of the dialkyl carbonate in a subsequent process step. To optimize the economics and energy efficiency of the process, additional devices are used for intermediate heating of the liquid streams in the apparatus.

Abstract: The invention relates to a process for production of diaryl carbonate combined with the electrolysis of the resultant alkali metal chloride-containing process wastewater. The process according to the invention makes possible, inter alia, improved utilization in electrolysis of the alkali metal chloride-containing solution obtained in the production of diaryl carbonate.